Searching for magnetic fields in the descendants of massive OB stars

We present the results of a recent survey of cool, late-type supergiants - the descendants of massive O- and B-type stars - that has systematically detected magnetic fields in these stars using spectropolarimetric observations obtained with ESPaDOnS at the Canada- France-Hawaii Telescope. Our observations reveal detectable, often complex, Stokes V Zeeman signatures in Least-Squares Deconvolved mean line profiles in a significant fraction of the observed sample of ∼30 stars.